This research is a continuation of a project consisting of a follow-up of 1473 adolescents who have been previously interviewed regarding drug and alcohol use patterns and related problems. The project will isolate factors which contribute to the development of substance abuse problems in late adolescence and to their persistence into early adulthood. All of the high risk subjects, originally contacted when they were referred for alcohol counselling or held in juvenile court detention, are being interviewed in the follow-up study. The treatment agencies in which the baseline data were collected will cooperate in recontacting their clients. Four specific sets of factors will be examined as predictive of stable heavy alcolol and drug intake and of the development of resultant problems. Independent variables hypothesized to relate to substance abuse outcomes are: (1) prior psychiatric diagnoses; (2) seriousness of deviant history; (3) initial levels of substance intake and related problems and (4) sex role attitudes and behaviors. The effects of these independent variables will be examined controlling for the type of intervention to which the youths were initially subjected, and for demographic characterisics. An assessment of the effects of these variables will allow for: (1) an evaluation of the relative importance of psychiatric and social histories in the development of symptoms of alcoholism or drug abuse in early adulthood; and (2) the establishment of psychiatric diagnostic criteria for alcoholism and drug abuse which will be useful in screening youthful populations.